


On the Motion of Heavenly Bodies

by Kanthia



Category: Good Omens (TV), Good Omens - Neil Gaiman & Terry Pratchett
Genre: Aggressively mathematical, M/M, Nudity
Language: English
Status: Completed
Published: 2019-08-05
Updated: 2019-08-05
Packaged: 2020-07-31 16:48:51
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,313
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20118352
Author URL: https://archiveofourown.org/users/Kanthia/pseuds/Kanthia
Summary: It is a well-beloved fact that Sir Isaac Newton's seminal work on gravity, Mathematical Principles of Natural Philosophy, was developed and and written alone in his home in Lincolnshire, in the company of only two: his gardener and his housekeeper.





	On the Motion of Heavenly Bodies

**Author's Note:**

> “He had been trying to measure the distance between the earth and God.” (Ursula Le Guin)

When Isaac Newton sat down to mathematically define the laws of gravity, and sought to explain how the thing that pulls a fruit to the earth might also be the same thing that causes the moon to meander about in the sky and Jupiter to wander across the horizon, he certainly hadn’t meant to shake the very foundations of the world. Nor, in deriving the first few fundamental theorems of calculus, had he intended to confound and bore high school students for the next four hundred years -- he’d just been scratching at an itch. In his own words, he’d been seeking to write a book in which one would need to feign no hypothesis; in truth, he’d been sent home after Cambridge was closed for two years on account of a resurgence of the Plague, and he was mightily bored.

His first stab at the _Philosophiæ Naturalis Principia Mathematica -- _Mathematical Principles of Natural Philosophy -- lacked sufficient explanation for the actual cause of gravitational pull, and was hand-annotated with his own frustrations and concerns. That copy disappeared for the better part of two centuries before an anonymous donor generously gave it to Newton’s old alma mater.

“Never did understand why you gave up Newt’s rough draft,” Crowley says, thumbing through a still unbelievably valuable second printing. He’s pleased to see he hasn’t lost his taste for those clever little Latin turns of phrase. “Thought you had a soft spot for firsts.”

“It was damaged by fire, dear,” Aziraphale calls, from a back room or another plane of existence. “I like them to be readable.”

Somebody -- perhaps William Blake, who worked through all sorts of frustrations as he painted the _Newton_, showing an anachronistically handsome Isaac scribbling circles at the bottom of the sea -- or perhaps Neil Gaiman’s Lucifer, tickling the ivories in a run-down piano bar -- would appreciate the image: the Serpent Itself, naked as the moment of Creation, lounging on a couch in a dusty old bookshop reading _Principia_; the Guardian of the East Gate, who watched the Morning Star fall and then rise again, entering the image carrying a steaming teapot, equally nude. It is a cool dawn in Soho.

Pythagoras, Aziraphale muses, loved to discuss mathematics at dawn. They’d watch the rise and fall of that same morning star, and it was always to his great delight that the star came to be known as Venus -- love, beauty, desire, prosperity. Fertility.

“Besides, those librarians at Cambridge were _so_ pleased to receive the original. It just -- filled me with glee, to see them so happy.”

Crowley has taken to tea, lately. It’s a nice change.

“D’you remember us with little Newt?”

“Newt Pulsifer? -- Witchfinder?”

“No, no. Isaac.”

“Isaac Newton? Of course. Odd young man.” Aziraphale sifts through his memory; on a yet undiscovered planet two hundred million light-years from Earth, the temperature shifts a fraction of a degree warmer. “Oh. That was the Second Coming, wasn’t it?”

* * *

  
It is a well-beloved fact of human nature that the best and the worst things come out of humanity without any intervention, divine or otherwise. Too much paperwork. Thus, for example, though Aziraphale had known one Poggio Bracciolini during his five-year sojorn in England in 1418 -- a period Bracciolini would later fondly recall as the least productive years of his life -- he had not been there eight months earlier when his discovery of Lucretius moldering in a German monastery had accidentally (accidentally!) started the Renaissance; neither had there been a gentleman dressed in fine black silk draped over Giovanni Boccaccio’s shoulder in or around 1353 while he had written _The Decameron_, sniggering at all the dirty jokes.

(Crowley had been vaguely aware, however, that one Geoffrey Chausseur, son of a vintner and moneylender, had later published a series of bawdy poems in Boccaccio’s style regarding some drunk peasants killing time at a crossroads in Canterbury. He'd been too busy languishing from what had been an otherwise profoundly boring century to read them while they were in active publication, and regretted it very much afterwards.)

So when Crowley had sauntered vaguely southward in the early sixteenth century, it hadn’t been to cause any particular trouble -- it was because he’d gotten a commendation from downstairs for whatever was going on in Florence, and figured he should have a look just in case anyone asked for specifics.

He’d never meant for all that nonsense in with the Augustinians to get so out of hand.

Sure, maybe he’d enjoyed what had happened to the Vatican. Maybe he’d laughed along with a Pope or two about how they planned to finance new churches. Nobody wanted to lay claim to the idea of indulgences -- whether it’d been Heaven’s cockup or Hell’s ingenuity -- but Crowley always did love a little twisting. After a while he’d gotten bored of listening to Machiavelli whine about princes and hitched a ride up to Germany with some Dominican friars, who had been commanded to drum up some funds to fix up old Saint Pete’s burial ground by offering absolution at a low low price. Fire sale on salvation, a church gets rebuilt, everyone wins!

Well, one of the monks up there, perhaps with or perhaps without the support of his patron and good buddy Augustin Fale, sends a letter to the archbishop outlining the first ninety-five reasons that came to mind as to why that was all sorts of bullshit. When the letter is ignored he thinks it best to get his ideas across by nailing it up on the door of the local church, and you know how these things go.

\-- Leave it to the English to cock that one up, too. Took the whole _Bible or Mass_ question and turned it into an _if a king divorces his wife in the woods and nobody hears it, does it make a Reformation _question.

So there was the Reformation, and grief between the Crown and the People, and lines were drawn and hovels chose sides and tensions mounted -- and then the King raises his standard in August 1642, declaring his intent to establish his God-given authority to rule over the ungrateful Parliament, and then the Parliament dug in their heels and declared their God-given authority to rule over the inbred pig of a King. There was to be war between the unwashed masses and their monarch, the likes of which England had not seen for more than four hundred years.

And on Christmas Day, an hour or two after midnight, in a dirty yeomans’ farm on the outskirts of Woolsthorpe-by-Colsterworth, Isaac was born.

* * *

It should be noted that the Agreement between the Serpent and the Guardian of the East Gate never included any stipulations about the joint raising of a child -- their later shenanigans regarding the boy-who-was-not-the-Adversary aside. They had, rather, stumbled into one another’s trajectories by chance: Aziraphale was sent to monitor the Civil War, and Crowley had heard through the grapevine that Beelzebub and Pestilence were getting together to give the Black Death one last hurrah in London.

They spent the night chasing the sunrise in the graveyard behind the local sanatorium, drinking to excess. The evening’s topic of conversation was whether or not the baby, born three months premature to a recently widowed woman and named Isaac in a fit of religious fervor, born early on Christmas Day on what by all accounts seemed like the End of the World or at least the End of England, was the Second Coming.

Neither of them had heard anything from their respective sides, of course; that was long after Aziraphale had stopped interpreting and Crowley had stopped snooping. The whole thing had just seemed so -- specifically timed.

So there was a silent agreement to stick around and keep an eye on the kid, and a nearby cottage miraculously became available to them that morning.

Isaac grew up spindly, asthmatic, foul-tempered, curious, insightful, prone to moments of clarity so brilliant it almost seemed divinely inspired. Reminded Aziraphale of Euclid in the best and worst ways, and Crowley of Archimedes for the same reasons. Had a weakness for gambling, but a heart as narrowly focussed as an arrow; read the Bible and loved God, but thought about it perhaps too deeply, and took it to task with a beautiful righteous fury. Retired himself to his little house in Lincolnshire after Cambridge closed during the Plague Years, joined only by his gardener and housekeeper.

“We’d go for long walks, and I’d ask him silly little questions about the movement of stars, and he’d get so red in the face as he tried to prove me wrong,” Aziraphale says, nestling himself into the crook of Crowley’s arm. They’re sitting upright, now, taking their tea, and neither has felt the need to put on any clothing. “Little trick I’d picked up from Socrates. And then he’d scamper back to his quarters and write for hours and hours, while you --”

“-- Swept up around him and egged him on, yes.”

Those were lovely years, the mid-1660s, the gardener and the housekeeper and Isaac furiously scribbling away, pretending there was no Civil War, no Plague, no Ineffable Plan; no atrocities in the Americas; pretending that the Ming Dynasty had never fallen, or that the Qing that followed it had transitioned in smoothly, that Cromwell’s Commonwealth had came in and out just as smoothly. The Ottomans were doing just fine under the Sultanate of Women, and Yeats would not write _The Second Coming _for two hundred fifty years, and Stradavari had just made his first violin -- and there a sable man gleefully arranging a terrible famine in Bengal, and Mount Etna was primed to blow. The Little Ice Age had hit its peak; the winters were terrible and the summers were dry, but there was always enough food on Isaac’s plate, and always beautiful things growing in his garden.

They’d have conversations, the two of them, while Isaac worked: long arguments that would stretch on for days, long silences that would stretch for hours. They’d fight about what the rainbow had really meant, whether or not it was right to keep Moses out of Israel for the seemingly minor crime of striking a rock, which side had been behind the Babylonians sacking the Second Temple, what would happen to dear Spinoza’s immortal soul after his excommunication. Isaac joined in, sometimes, seemingly content to weigh in on abstract religious hypotheticals.

There had been -- well, there had been this little turning-over in Crowley, a sort of shift in his internal temperature. He’d not thought too much on it; thinking too much had gotten him into all sorts of trouble in the past, but that was when -- that was when --

“-- Oh,_ Lord_,” Crowley says, the Word burning the inside of his mouth, and a brilliant hurricane of methane and diamonds starts up near Neptune’s north pole, and a writer in Salisbury feels a sudden chill.

That was when he’d first thought that maybe,_ just maybe_, eternity wouldn’t be so bad if it meant long conversations about abstract religious hypotheticals in green gardens.

Aziraphale miracles the mug back together, and the spilled tea out of the fibers of his _Principia_. In his glee he’s manifested a few dozen eyes, but Crowley’s too busy dealing with his own personal revelation to notice.

“Did you know -- did you know this whole time?”

“We can sense love, dear.”

“And when did _you_ know?”

“Oh, I think it was just before the Flood. You came up to me, do you remember? You asked me what I thought of it all. And it occurred to me that nothing had ever cared what I thought.”

“‘Course I remember. I was _there_.”

“Well.” He places the mug, gently, back into Crowley’s hands. “That’s when I knew.”

Crowley, lacking anything better to say, slings his free arm over Aziraphale’s shoulder. Aziraphale tucks his spare eyes away. The lights in the bookshop dim; Carbon-12 resets to its correct atomic mass; the Riemann Hypothesis remains beautiful and unproven.

Then, finally, long after the bookshop should have opened and the world should have ended, Crowley breaks the silence. “Beautiful stuff, calculus.”

_Principia_ would, of course, be impossible without it, the mathematics of infinitely small and infinitely large numbers, the mathematics of taking ideas to their limits, the mathematics of philosophy, of dreams; Archimedes and Zhu Chongzhi had proposed circular and spherical areas by means of drawing shapes with infinitely many sides, and Mādhava that a cosine wave had much in common with an infinite polynomial, and Fermat that two things that are very closer together are both functionally and mathematically equal.

And Newton, standing on the shoulders of all the giants who wandered through those woods before him, took that limit as truth: you take two disparate points and move them closer and closer together, until the distance between them becomes functionally meaningless, and in that moment you find your true direction.

To Newton, then, calculus was the language that describes heavenly bodies in motion; and to Liebniz, who made the same discovery at the same time -- without a single angel or demon involved, mind you -- calculus was a purely metaphysical thought experiment, the abstract language of change. At its very heart is the moment where zero and infinity serve the same purpose.

Einstein was right: God is a mathematician, not a statistician; at its heart, the universe operates on process, not on random chance; God plays cards, not dice. Leave it to one of us to figure out such an obvious fact.

“Beautiful stuff,” Aziraphale agrees, and disengages himself from the home he’s made in Crowley’s arms, stands up and stretches, puts on Vivialdi, dusts and straightens and thinks about having wagyu beef for dinner. Crowley enjoys the sight of Aziraphale dusting and straightening and thinking. The sun ambles across the sky with its exact mathematical precision, and all things go on and on and on and on.

**Author's Note:**

> find me posting incoherently about math on [tumblr](https://kanthia.tumblr.com/)


End file.
